With the miniaturization of products, manual assembly is getting difficult, and this assembly method can on longer meet the requirements of high-performance micro or small devices. To develop automated assembly equipment is an effective way to solve this problem. Due to the diversified assembly tasks, and factors such as device improvements, product upgrades, shortening of the research and development (R&D) cycle, the micro/ small assembly equipment developed is required to respond rapidly to the product changes. Therefore, the development of flexible assembly systems is the key to cope with the challenge. This paper introduces main technologies and methods for improving the flexibility of micro/ small assembly systems, namely modularization, and automatic exchange of manipulating tools and micro grippers for miniature parts. This paper the research progress. On this basis, the researchers proposed the system architecture of the flexible micro assembly system for a certain type miniature devices. The automated equipment for precision assembly of small devices developed based on the architecture is briefly introduced. This paper aims to provide reference for the development of flexible micro/ small assembly equipment.